Touch display device and driving method thereof

ABSTRACT

A touch display device includes a display panel and a transparent conductive pattern layer. The display panel has a display side and a back side opposite to each other, and includes a plurality of data lines extending along a first direction. The data lines transmit a plurality of touch signals and display signals. The transparent conductive pattern layer is disposed on the display side, and includes a plurality of sensing electrodes extending along a second direction. The sensing electrodes intersect and are electrically insulated from the data lines to form a touch sensing element.

This application claims the benefit of U.S. Provisional Application Ser.No. 62/027,236, filed Jul. 21, 2014, the subject matter of which isincorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates in general to a touch display device and a drivingmethod thereof, and more particularly, to a touch display device thatutilizes data lines of a display panel and a transparent conductivepattern layer disposed on the display panel as a touch sensing element,and a driving method thereof.

2. Description of the Related Art

In the recent years, with extensive developments and applications ofconsumer electronic products, the number of application productsemploying touch display devices that integrate touch control and displayfunctions also continues to expand. Some examples of these applicationproducts include mobile phones, GPS navigation systems, tabletcomputers, personal digital assistants (PDAs), and laptop computers.Recently, manufacturers are also dedicated in developing wearabledevices having a touch function. A conventional touch display panel isformed by directly attaching a touch panel with a display panel. Theoverall thickness and weight of such panels are greater than those ofone single display panel, resulting in a burden in user portability.Therefore, there is a need for a solution for reducing the thickness ofa touch display device.

SUMMARY OF THE INVENTION

It is a primary object of the present invention to provide a touchdisplay device for reducing the thickness of the touch display device.

To achieve the above object, the present invention provides a touchdisplay device. The touch display device includes a display panel and atransparent conductive pattern layer. The display panel has a displayside and a back side opposite to each other, and a plurality data lines.The data lines extending along a first direction, and transmit aplurality of touch signals and display signals. The transparentconductive pattern layer is disposed on the display side, and includes aplurality of sensing electrodes extending along a second direction. Thesensing electrodes intersect and are insulated from the data lines toform a touch sensing element.

To achieve the above object, the present invention further provides adriving method of a touch display device. The touch display deviceincludes a display panel, and a transparent conductive pattern layerdisposed on a display side of the display panel. The display panelincludes a plurality of data lines extending along a first direction.The transparent conductive pattern layer includes a plurality of sensingelectrodes extending along a second direction. The sensing electrodesintersect and are insulated from the data lines. The driving methodincludes following steps. In a display period, a display signal istransmitted to at least one of the data lines. In a touch controlperiod, a touch signal is transmitted to at least one of the data lines,and a sensing signal is received from at least one of the sensingelectrodes corresponding to the data lines.

In the touch display device of the present invention, a touch sensingelement is formed by the data lines and the transparent conductivepattern layer, and a touch electrode layer conventionally used fortransmitting touch signals can be omitted, so as to effectively reducethe thickness and production costs of the touch display device. That is,the present invention realizes the touch function without needing toattach an additional touch electrode layer (e.g., an indium tin oxide(ITO) layer).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a section view of a touch display device according to a firstembodiment of the present invention;

FIG. 2 is a top view of an array substrate according to the firstembodiment of the present invention;

FIG. 3 is a top view of data lines and a transparent conductive patternlayer according to the first embodiment of the present invention;

FIG. 4 is a circuit diagram of a touch display device of the presentinvention;

FIG. 5 is a flowchart of a driving method of a touch display device ofthe present invention;

FIG. 6 is a timing diagram of a gate signal transmitted by a gate line,a touch signal and a display signal transmitted by a data line, and asensing signal sensed by a sensing electrode of the present invention;

FIG. 7 is a top view of a sensing electrode according to a secondembodiment of the present invention;

FIG. 8 is a section view of a touch display device according to a thirdembodiment of the present invention; and

FIG. 9 is a section view of a touch display device according to a fourthembodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The above and other aspects of the invention will become betterunderstood with regard to the following detailed description of thepreferred but non-limiting preferred embodiments. The followingdescription is made with reference to the accompanying drawings.

FIG. 1 shows a section view of a touch display device according to afirst embodiment of the present invention. As shown in FIG. 1, a touchdisplay device 100 includes a display panel 102 and a transparentconductive pattern layer 104. The display panel 102 has a display side102 a and a back side 102 b opposite each other. The transparentconductive pattern layer 104 is disposed on the display side 102 a. Inthe embodiment, the display panel 102 is a liquid crystal panel (LCD),e.g., a twisted nematic (TN) LCD, a vertically aligned LCD, or anorganic light emitting diode (OLED) display panel. In the embodiment,the display panel 102 includes an array substrate 106, a color filtersubstrate 108 and a liquid crystal layer 110. The array substrate 106and the color filter substrate 108 are disposed opposite to each other,and the liquid crystal layer 110 is disposed between the array substrate106 and the color filter substrate 108. In the embodiment, the arraysubstrate 106 is located on the color filter substrate 108, and so anouter surface of the array substrate 106 is the display side 102 a andan outer surface of the color filter substrate 108 is the back side 102b.

More specifically, refer to FIG. 2 and FIG. 3 as well as FIG. 1. FIG. 2shows a top view of an array substrate according to the first embodimentof the present invention. FIG. 3 shows a top view of data lines and atransparent conductive pattern layer according to the first embodimentof the present invention. As shown from FIG. 1 to FIG. 3, the arraysubstrate 106 includes a first substrate 112 and a plurality of datalines 114. The first substrate 112 has a first inner surface 112 and thedisplay side 102 a opposite to each other. The data lines 114 aredisposed between the first inner surface 112 a of the first substrate112 and the liquid crystal layer 110, and extend along a first direction116. The transparent conductive pattern layer 104 includes a pluralityof sensing electrodes 118 extending along a second direction 120different from the first direction 116. As such, the sensing electrodes118 may intersect the data lines 114, and are electrically insulatedfrom the data lines 114 via the first substrate 112. In the embodiment,for example, the transparent conductive layer 104 may include indium tinoxide (ITO), indium zinc oxide (IZO), aluminum zinc oxide, or aluminumtin oxide. It should be noted that, the sensing electrodes 118 and thedata lines 114 may couple to each other so as to generate sensingcapacitors C between the sensing electrodes 118 and the data lines 114,such that the sensing electrodes 118 and the data lines 114 may form atouch sensing element. In the embodiment, the data lines 114 may be usedto transmit touch signals and display signals. Thus, not only that thedisplay panel 102 is allowed to display an image, but also the touchsensing element may detect a position of touch object, e.g., a finger ora stylus, touching or approaching the touch display device 100 throughsensing signals from the sensing electrodes 118.

The array substrate 106 may further include a plurality of gate lines122, a plurality of thin-film transistors (TFTs) 124 and a plurality ofpixel electrodes 126 disposed between the liquid crystal layer 110 andthe first inner surface 112 a. The gate lines 122 extend along thesecond direction 120, and intersect the data lines 114. Each of the TFTs124 is disposed in a region surrounded by two adjacent gate lines 118and two adjacent data lines 114, and includes a gate 128, a gateinsulation layer 130, a semiconductor island 132, a source 134 and adrain 136. Each gate 128 is connected to one corresponding gate line122, i.e., the gates 128 of the TFTs 124 arranged at the same row areelectrically connected to the same gate line 122. In the embodiment, thegates 128 and the gate lines 122 are formed by a first metal patternlayer M1. The gate insulation layer 130 covers the first metal patternlayer M1 and the first inner surface 112 a. The semiconductor island 132is disposed on the gate insulation layer 130 corresponding to gates 128,and may be formed by a non-silicon, doped non-silicon, polysilicon ormetal oxide semiconductor, for example. The sources 134 and the drains136 are disposed on the semiconductor island 132 and the gate insulationlayer 130, and are disposed correspondingly at two sides of the gates128. Each source 134 is electrically connected to one corresponding dataline 114, i.e., the drains 134 of the TFTs 124 arranged at the samecolumn are electrically connected to the same data line 114. Forexample, the sources 134, the drains 136 and the data lines 114 areformed by a second metal pattern layer M2. The type of TFTs in thepresent invention is not limited to the above example, and may be othertypes, e.g., top-gate TFTs. In the embodiment, the pixel electrodes 126are disposed on the drains 136 and the gate insulation layer 130, andare electrically connected to the drains 136. Each of the pixelelectrodes 126 extends to overlap with the corresponding gate line 122to form a storage capacitor Cst. The storage capacitor in the presentinvention is not limited to be formed by a pixel electrode and a gateline. In another embodiment, the array substrate may further includecommon lines, and the storage capacitors are formed by the pixelelectrodes that mutually couple with the common lines.

The color filter substrate 108 may include a second substrate 138, ablack matrix layer 140, a color filter layer 142 and a common electrodelayer 144. The second substrate 138 has a second inner surface 138 a anda back side 102 b opposite to each other. The liquid crystal layer 110is disposed between the first inner surface 112 a of the first substrate112 and the second inner surface 138 of the liquid crystal layer 110.The color filter layer 142 is disposed between the liquid crystal layer110 and the second inner surface 138 a, and is disposed correspondinglyto the pixel electrodes 126. The common electrode layer 144 is disposedbetween the black matrix layer 140 and the liquid crystal layer 110 aswell as between the color filter layer 142 and the liquid crystal layer110. The common electrode layer 144, the pixel electrodes 126 and theliquid crystal layer 110 form a liquid crystal capacitor Clc. Forexample, to flatten the common electrode layer 144, a flat layer 146 maybe further disposed between the color filter layer 142 and the blackmatrix layer 140. Thus, the common electrode layer 144 may provide theliquid crystal layer 110 with an even electric field. In the embodiment,for example, the first substrate 112 and the second substrate 138 may beformed by transparent substrates, e.g., glass, acrylic, quartz, sapphireor plastic. In another embodiment, the array substrate and the colorfilter substrate may further include an alignment film for determiningalignment directions of liquid crystal particles.

In the embodiment, as the display panel 102 is a liquid crystal panel,the display touch device 100 may further include a backlight module 148,for example. The backlight module 148 is disposed facing the back side102 b, and provides light for image display. The touch display device100 may further include a first polarization film 150 and a secondpolarization film 152 respectively disposed on the display side 102 aand the back side 102 b, and the transparent conductive pattern layer104 is disposed between the first polarization film 150 and the displaypanel 102. The polarization direction of the first polarization film 150and the polarization direction of the second polarization film 152 maybe determined according to the alignment directions of the alignmentfilm and operation principles of the display panel 102. For example,when the alignment directions of the alignment film are perpendicular toeach other and the display panel 102 is a normally black type, thepolarization direction of the first polarization film 150 isperpendicular to the polarization direction of the second polarizationfilm 152. It should be noted that the present invention is not limitedto the above example.

FIG. 4 shows a circuit diagram of a touch display device of the presentinvention. As shown in FIG. 4, in the embodiment, the data line 114 andthe sensing electrodes 118 may be electrically connected to a controlelement 154. The control element 154 provides touch signals and displaysignals to the data lines 114 and receive sensing signals from thesensing electrodes 118.

A driving method of a touch display device according to an embodiment ofthe present invention, and how image display and touch sensing functionsare simultaneously provided are described in detail below. FIG. 5 showsa flowchart of a driving method of a touch display device of the presentinvention. As shown in FIG. 5, the driving method of the touch displaydevice 100 includes following steps.

In step S10, in a display period DT, a display signal F is transmittedto at least one of the data lines 114, and a gate signal is transmittedto at least one of the gate lines.

In step S12, in a touch control period TT, a touch signal T istransmitted to at least one of the data lines 114, and a sensing signalRx is received from at least one of the sensing electrodes 118corresponding to the at least one data line 114.

FIG. 6 shows a timing diagram of a gate signal transmitted by a gateline, a touch signal and a display signal transmitted by a data line,and a sensing signal received from a sensing electrode. As shown in FIG.6, in the embodiment, a driving period of the touch display device 100may include a display period DT and a touch control period TT, which donot overlap with each other.

Referring to FIG. 4 to FIG. 6, in step S10, the display signal F may betransmitted to the data line 114 via the control element 154. Further,gate signals G1 to Gn corresponding to the display signal F transmittedby the data line 114 may be transmitted to the corresponding gate lines112 via a gate driving circuit or another control element to turn on thecorresponding TFT 124, so as to further provide the pixel electrodes 126with a desired pixel voltage. Further, a common voltage is applied tothe common electrode layer 144. At this point, the touch display device100 is allowed to display an image.

In step S12, since the touch control period TT and the display period DTdo not overlap, the control element 154 may transmit the touch signal Tdifferent from the display signal F to the data line 114, and receivethe sensing signals Rx from the sensing electrodes 118 corresponding tothe data line 114 at the same time. As such, the control element 154 maydetect the position of an object touching or approaching the touchdisplay device 100. It should be noted that, in the touch control periodTT, the gate lines 122 do not transmit gate signals to avoid fromturning on the TFTs 124, so as to further prevent the touch signal Tfrom affecting the voltage difference between the pixel voltage and thecommon voltage. Thus, the image displayed by the touch display device100 is free from interference of touch sensing.

In the embodiment, the display period DT is the time that the displaypanel displays one frame. Therefore, the touch display device 100 maytransmit the touch signal T to the data line and receive the sensingsignal Rx between display periods DT of displaying different frames. Inanother embodiment, the display period may be divided into two periods,which respectively correspond to different gate signals of the sameframe. The touch control period may be located between the periods ofany two adjacent display signals to prevent the displayed image frominterference of the touch signal.

It should be noted that, in the touch display device of the presentinvention, as the display signal F and the touch signal T may beintegrated into the touch signal and the display signals D1 to Dn, thedata lines not only serve as conducting lines that the display paneluses for transmitting the pixel voltage, but also form a touch sensingelement with the transparent conductive pattern layer. As such, whileomitting the touch electrode layer for transmitting touch signals, thetouch display device of the present invention is capable of realizingtouch sensing to further effectively reduce the thickness and costs ofthe touch display device.

The touch display device of the present invention is not limited to theabove embodiment. Other embodiments are further disclosed below. For thesake of simplicity and to emphasize differences between the embodimentsand variations, the same elements are represented by the samedenotations, and associated description is omitted.

FIG. 7 shows a top view of a sensing electrode according to a secondembodiment of the present invention. Referring to FIG. 7, compared tothe first embodiment, a sensing electrode 202 of the embodiment includesa plurality of strip-like electrodes 204 and a comb pattern. Morespecifically, each sensing electrode 202 includes a plurality ofstrip-like electrodes 204 and a connecting electrode 206. The strip-likeelectrodes 204 extend along the second direction 120, and the connectingelectrode 206 connects end points of the strip-like electrodes 204.

FIG. 8 shows a section view of a touch display device according to athird embodiment of the present invention. As shown in FIG. 8, comparedto the first embodiment, a display panel 302 of a touch display device300 of the embodiment may be an in-plane switching (IPS) LCD panel, andouter surfaces of an array substrate 304 and a color filter substrate306 are respectively the back side 102 b and the display side 102 a.Thus, the transparent conductive pattern layer 104 is disposed on theouter surface of the color filter substrate 306.

More specifically, in the array substrate 304 of the embodiment, thefirst substrate 112 has the back side 102 b, and the second substrate138 has the display side 102 a. The transparent conductive pattern layer104 is disposed between the display side 102 a and the firstpolarization film 150. Further, TFTs 308 of the embodiments are top-gateTFTs, and so gates 310 are disposed between sources 312 and the liquidcrystal layer 110 and between drains 314 and the liquid crystal layer110. A pixel electrode pattern 316 and the common electrode pattern 318of the array substrate 304 are disposed between the liquid crystal layer110 and the first inner surface 112 a, and are patterned electrodes.Thus, the voltage difference between the pixel electrode pattern 316 andthe common electrode pattern 318 may provide the liquid crystal layer110 with a horizontal electric field to achieve a wide viewing angle.For example, the array substrate 304 may further including a lightshielding layer 320 and an insulation layer 322. The light shieldinglayer 320 is disposed on the first inner surface 112 a, and theinsulation layer 322 covers the light shielding layer 320 and the firstinner surface 112 a. The light shielding layer 320 may be formed by thefirst metal pattern layer M1. A semiconductor island 324 is disposed onthe insulation layer 322, and the light shielding layer 320 is disposedbetween the semiconductor island 324 and the first inner surface 112 a,such that the light shielding layer 320 may shield against lightgenerated by the backlight module 148 disposed at the back side 102 b toprevent the light from illuminating the part of the semiconductor island324 that serves as a passage. The sources 312 and the drains 314 formedby the second metal pattern layer M2 are disposed on the semiconductorisland 324. A gate insulation layer 326 covers the second metal patternlayer M2 and the semiconductor island 324. The gates 310 are disposed onthe gate insulation layer 326, and are disposed correspondingly to thesemiconductor island 324. The gates 310 may be formed by a third metalpattern layer M3. The array substrate 304 further includes a dielectriclayer 328, the pixel electrode pattern 316 and the common electrodepattern 318. The dielectric layer 328 covers the gates 310 and the gateinsulation layer 326, and the gate insulation layer 326 and thedielectric layer 328 have a plurality of through holes TH that revealthe drains 314. Thus, the pixel electrode pattern 316 may electricallyconnect to the drains 314 via the through holes TH. The pixel electrodepattern 316 and the common electrode pattern 318 are disposed on thedielectric layer 328. In the embodiment, the pixel electrode pattern 316and the common electrode pattern 318 may be formed by the sametransparent conductive pattern layer, for example. Further, as thedisplay panel 302 of the embodiment is an IPS LCD panel, the colorfilter substrate 306 need not be provided with a common electrode layer.Thus, the sensing capacitors C formed by the transparent conductivepattern layer 104 and the data lines 114 do not become inoperable whenshielded by the common electrode layer. In another embodiment, the TFTsmay be bottom-gate TFTs, and the array substrate may accordingly excludethe shielding layer and the insulation layer.

FIG. 9 shows a section view of a touch display device according to afourth embodiment of the present invention. As shown in FIG. 9, thedisplay panel 302 of a touch display device 400 of the embodiment isalso an IPS LCD panel. However, compared to the third embodiment, theouter surface of the array substrate 304 of the embodiment is a displayside 402 a, and the outer surface of the color filter substrate 306 is aback side 402 b. Thus, the transparent conductive pattern layer 104 isdisposed on the outer surface of the array substrate 304, and thebacklight module 148 is disposed facing the outer surface of the colorfilter substrate 306. The array substrate 304 and the color filtersubstrate 306 of the embodiment are identical to those of the thirdembodiment, and associated description shall be omitted herein.

In conclusion, in the touch display device of the present invention, thedata lines may be used to transmit touch signals containing touchsignals and image data signals as well as display signals. Thus, thedata lines can not only serve as conducting wires that the display paneluses for transmitting the pixel voltage, but also form a touch sensingelement with the transparent conductive pattern layer. Therefore, thetouch display device of the present invention eliminates a touchelectrode layer for transmitting touch signals to effectively reduce thethickness and costs of the touch display device.

While the invention has been described by way of example and in terms ofthe preferred embodiments, it is to be understood that the invention isnot limited thereto. On the contrary, it is intended to cover variousmodifications and similar arrangements and procedures, and the scope ofthe appended claims therefore should be accorded the broadestinterpretation so as to encompass all such modifications and similararrangements and procedures.

What is claimed is:
 1. A touch display device, comprising: a displaypanel, having a display side and back side opposite to each other,comprising a plurality of data lines extending along a first direction,the data lines configured to transmit a plurality of touch signals anddisplay signals; and a transparent conductive pattern layer, disposed onthe display side, comprising a plurality of sensing electrodes extendingalong a second direction, the sensing electrodes intersecting and beingelectrically insulated from the data lines to form a touch sensingelement.
 2. The touch display device according to claim 1, wherein thedisplay panel further comprises: a first substrate, having a first innerside and the display side opposite to each other; a second substrate,disposed opposite the first substrate, having a second inner surface andthe back side opposite to each other; and a liquid crystal layer,disposed between the first inner surface of the first substrate and thesecond inner surface of the second substrate; wherein, the data linesare disposed between the first inner surface and the liquid crystallayer.
 3. The touch display device according to claim 2, wherein thedisplay panel further comprises: a plurality of gate lines, disposedbetween the liquid crystal layer and the first inner surface,interesting and being insulated from the data lines; a plurality ofthin-film transistors (TFTs), disposed between the liquid crystal layerand the first inner surface, each of the TFTs comprising a gate, asource and a drain, each of the gates electrically connecting to one ofthe corresponding gate lines, each of the sources electricallyconnecting to one of the corresponding data lines; a plurality of pixelelectrodes, disposed between the liquid crystal layer and the firstinner surface, electrically connecting to the drains; a black matrixlayer, disposed between the liquid crystal layer and the second innersurface; a color filter layer, disposed between the liquid crystal layerand the second inner surface; and a common electrode layer, disposedbetween the liquid crystal layer and the color filter layer.
 4. Thetouch display device according to claim 2, wherein the display panelfurther comprises: a plurality of gate lines, disposed between theliquid crystal layer and the first inner surface, intersecting and beinginsulated from the data lines; a plurality TFTs, disposed between theliquid crystal layer and the first inner surface, each of the TFTscomprising a gate, a source and a drain, each of the gates electricallyconnecting to one of the corresponding gate lines, each of the sourceselectrically connecting to one of the corresponding data lines; aplurality of pixel electrode patterns, disposed between the liquidcrystal layer and the first inner surface, electrically connecting tothe drains; a common electrode pattern, disposed between the liquidcrystal layer and the first inner surface; a black matrix layer,disposed between the liquid crystal layer and the second inner surface;and a color filter layer, disposed between the liquid crystal layer andthe second inner surface.
 5. The touch display device according to claim1, wherein the display panel further comprises: a first substrate,having a first inner side and the back side opposite to each other; asecond substrate, disposed opposite to the first substrate, having asecond inner surface and the display side; and a liquid crystal layer,disposed between the first inner surface of the first substrate and thesecond inner surface of the second substrate; wherein, the data linesare disposed between the first inner surface and the liquid crystallayer.
 6. The touch display device according to claim 5, wherein thedisplay panel further comprises: a plurality of gate lines, disposedbetween the liquid crystal layer and the first inner surface,interesting and being insulated from the data lines; a plurality ofTFTs, disposed between the liquid crystal layer and the first innersurface, each of the TFTs comprising a gate, a semiconductor island, asource and a drain, each of the gates electrically connecting to one ofthe corresponding gate lines, each of the sources electricallyconnecting to one of the corresponding data lines; a plurality of pixelelectrode patterns, disposed between the liquid crystal layer and thefirst inner surface, electrically connecting to the drains; a commonelectrode pattern, disposed between the liquid crystal layer and thefirst inner surface; a black matrix layer, disposed between the liquidcrystal layer and the second inner surface; and a color filter layer,disposed between the liquid crystal layer and the second inner surface.7. The touch display device according to claim 6, wherein the gates aredisposed between the sources and the liquid crystal layer and betweenthe drains and the liquid crystal layer, and the display panel furthercomprises a light shielding layer disposed between the semiconductorislands and the first inner surface.
 8. The touch display deviceaccording to claim 1, wherein each of the sensing electrodes has acomb-like pattern and comprises a plurality of strip-like electrodes anda connecting electrode, the strip-like electrodes extend along thesecond direction, and the connecting electrode connects end points ofthe strip-like electrodes.
 9. The touch display device according toclaim 1, wherein the data lines and the sensing electrodes electricallyconnect to a control element, and the control element provides the touchsignals and the display signals.
 10. The touch display device accordingto claim 1, further comprising a backlight module disposed facing theback side.
 11. The touch display device according to claim 1, furthercomprising a first polarization film and a second polarization filmrespectively disposed on the display side and the back side, wherein thetransparent conductive pattern layer is disposed between the firstpolarization film and the display panel.
 12. A driving method of a touchdisplay device, the touch display device comprising a display panel anda transparent conductive pattern layer disposed on a display side of thedisplay panel, the display panel comprising a plurality of data linesextending along a first direction, the transparent conductive patternlayer comprising a plurality of sensing electrodes extending along asecond direction, the sensing electrodes intersecting and beingelectrically insulated from the data lines; the driving methodcomprising: in a display period, transmitting a display signal to atleast one of the data lines; and in a touch control period, transmittinga touch signal to at least one of the data lines, and receiving asensing signal from at least one of the sensing electrodes correspondingto the data lines.
 13. The driving method according to claim 12, whereinthe display panel further comprises a plurality of gate lines; and thegate lines intersect and are electrically insulated from the data lines,and transmit a gate signal to at least one of the gate lines in thedisplay period.
 14. The driving method according to claim 12, whereindisplay period does not overlap with the touch control period.